Discharge effects on materials consisting wholly or in part of acetyl cellulose



Patented Dec. 6, 1927. w

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LEO SMITH, OF MANCHESTER, ENGLAND, ASSIGNOR '10 BRITISH DYESTUFFB COB- PORATION LIMITED, OF MANCHESTER, ENGLAND.

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' Io Drawing. Application filed September 23, 1926, Serial 1W0. 187,888, and in Great Britain November 85,

It is well known that the reduction discharge processes based on sodium sulphoxy- 'late in general use for the production of discharge effects on cotton, silk and woolen materials are not effective when applied to acetyl cellulose. For this reason a large and important range of designs cannot be produced at the present time on materials consisting either wholly or in part of acetyl cellulose.

Atypical reduction discharge is that in which ,use is made of products sold under the various trade names and depending upon their sodium formaldehyde-sulphoxylate content for their reducing properties.

Such typical reduction discharge printing pastes containing sodium sulphoxylate, will give a perfectly white discharge when applied by the usual methods to cotton, or other cellulose materials, which-have for instance been dyed with chlorazol fast orange G, (dianil brown 3GO-Color Index No. 273) but it has very little efi'ect when applied by the same methods to acetyl cellu ose dyed with the same dyestufi.

I have found that the addition of sulphocyanides to the reduction dischar printing paste containing sodium sulphoxy ate brings about complete reduction of all colours which are dischargeable when dyed on the usual textile materials by the use of the aforesaid discharge printing paste, but which hitherto have not been found dischargeable' by the same process when dyed on acetyl cellulose materials. The sulpho-cyanides of calcium, barium and ammonium are typical but I do not limit myself to these. 7

Further, azo dyestufis specially designed for the dyeing of acetyl cellulose materials such as the Ionamine series, manufactured b British Dyestufi's Corporation Limited. l he dyestuffs formed by coupling dimethyl or diethyl-aniline with diazotised 5-nitro-oanisidine or with diazotised 2:4-dinitroaniline (known as S. R. A. Beds, 1, 3 and 5), or by couplin diphenylamine with. (S. R. A. Orange 1 or other S. R. A. dyestuifs manufactured by the British Celanese Limited, which also are not satisfactorily discharged by the usual discharge printing pastes containing sodium sulphoxylate, are found to give perfect whites if sulphocyanides are added.

Dependent for its success upon the at tamment of a satisfactory white discharge of the ground colour, the so-called coloured dlscharge process, in which a suitable basic colour is added to the discharge printing paste containing sodium sulphoxylate, is correspondingly improved by the addition of sulphpcyanides to the coloured discharge prmtmg pastes.

Ewample 1.

. A fabric consisting of cotton and acetyl cellulose 1s dyed in the customary manner with chlorazol fast Orange Grand is afterwards printed with a discharge printing colour made up as follows 15 ammes sodium formaldehyde-sulphoxy ate are dissolved in 70 grammes of gum tragacanth solution-containing 30 grammes of gum tragacanth in one litre j Ewample 2.

Material consisting of acetyl cellulose isdyed in the usual manner with the formaldehyde bisulphite compound of 3-nitro-4'- aminoazobenzene, obtained by coupling m-nitrodiazobenzene with aniline, and treating the product with formaldehyde and sodium bisulphite solution and is afterwards diazotised and developed with beta-na hthol in the customary way. It is then printed and after-treated as described in Example 1. 1

- Example 3.

Material consisting of acetyl cellulose is dyed in the usual way with S. R. A. Orange 1 (British Oelanese Ltd.) which is 4-nitrobenzeneazodiphenylamine and then it is printed and after-treated as described in Example 1.

Example 4.

Material consisting of acetyl cellulose is dyed, printed and after-treated as ribed v in Example 1, except that Thionine Blue GO (color Index No, 926) is added to the discharge printing colour.

What I claim and desire to secure by Letters Patent is: y

1. The process of making a pre aration for the reduction of discharge e ects on acetyl cdllulose materials which comprises the addition of sulphocyanides to. the usual sodium vformaldehydesulphoxylate v discharge printing pastes.

2. As a new article of manufacture, a

. preparation for the production of discharge efiects on materials containing acetyl cellulose comprisin the usual sodmm formaldehyde-sulphoxyl ate discharge printing paste and also comprising a sulphocyanide.

3. As a new article of manufacture, a preparation for the'production of discharge effects on materials containin acetyl cellulose com'prisin the usual SOdlllID formaldehyde-sulphoxy ate discharge printing paste and also comprising a sulphocyanide of an alkaline earth metal. a

4. As a new article of manufacture, a preparation for the production of discharge effects on materials containin acetyl cellulose comprisin the usual sodium formaldehyde-sulphoxylate discharge printing paste and also comprising calcium sulphocyanide.

5. As a new article of manufacture, a

preparation for'the production of discharge effects on materials containing acetyl cellu-' lose comprising sodium formaldehyde-sulphoxylate, gum tragacanth, calcium sulphocyanide and water substantially in the proportions of 15 parts of sodium formaldeyde sulphoxylate, 2.1- parts of gum tragacanth, 11 parts of calcium sulphocyanide and 71.4 parts of water, the parts being by weight.

In testimony whereof I have signed my name to this specification;

LEO SMITH. 

